Risk estimation of ABO and Rho(D) incompatibility in persons with mono- and polyphyletic surnames in Monterrey, Mexico. Comparison with other Mexican populations.

ABO and Rh(o)(D) blood groups were determined in 3813 males and females affiliated with the Instituto Mexicano del Seguro Social (IMSS) who are residents of the Monterrey Metropolitan Area (MMA) in northeastern Mexico. They were selected by their monophyletic or polyphyletic surnames. The ABO and Rh(o)(D) blood group phenotypes and gene frequencies were determined and based upon these, the risk of incompatibilities was estimated for both marriages (MI) and maternal-fetal incompatibility (MFI). These were compared with those estimated for other populations of residents in the MMA, and in other locations in Mexico, as well as with the two most important ancestral populations, Spanish and Tlaxcaltecan Mexican Indians, with the hypothesis that the percent of risk of ABO and Rh(o)(D) MI and MFI are greater in the population with monophyletic surnames than those with polyphyletic surnames. It was found that for persons with monophyletic and polyphyletic surnames, as well as for the other populations in the MMA and other places in Mexico, their ABO and Rho(D) MI and MFI percent of risk are intermediate to the ones estimated for their ancestry. The percentages of MI and MFI are higher for the persons with monophyletic than for the ones with polyphyletic surnames, other populations from the MMA and those from other locations in Mexico. The risks are higher when the similarity with Spanish increases and are lower when their similarities with the Mexican Indians increase.

Orally administered gossypol has no effect on eight hamster erythrocytic enzymes.

The effectiveness of gossypol as an antifertilizing agent is due to the severe injuries or death that this drug produces on spermatozoa and spermatides. Several in vitro and in vivo studies have shown that spermatozoal lactic and malic dehydrogenases are inhibited by gossypol; and that these are more susceptible than the somatic enzymes. Notwithstanding, the in vivo effects on other somatic enzymes have been poorly analyzed. The present study shows that gossypol did not produce toxic effects on eight erythrocytic enzymes of male hamsters that were fed daily with 20 mg of gossypol/kg, for 1, 3, 5 or 10 days. The enzymatic activities analyzed were: adenylate kinase, hexokinase, glucose-6-phosphatase, glucose phosphoisomerase, phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase, phosphoglyceratokinase and pyruvate kinase.

Frequency and origin of G-6-PD deficiency among icteric newborns in the metropolitan area of Monterrey, Nuevo León, Mexico.

829 icteric newborn males were studied in order to have more information about the frequency of the G-6-PD deficiency and its origin in the population of the Monterrey Metropolitan area (MMA), in northeastern Mexico. For each subject information about the maternal grandparents' birthplace (states of Mexico) was gathered. The newborns were grouped into five geographic areas. It was found that the frequency of G-6-PD deficiency is higher in icterics than in normal newborns. The grandparents of the deficient newborns with variant B belonged to the northeastern states of Mexico where more European genetic contribution was present whereas most of the grandparents of the A- deficient newborns were from the gulf coast states, where the genetic contribution was African.

Relationships by isonymy between persons with monophyletic and polyphyletic surnames from the Monterrey metropolitan area, Mexico.

Three thousand two hundred eleven males and females who resided and were interviewed in the Monterrey metropolitan area in northeastern México were selected for having 1 of 10 common selected surnames as either their patronymic or matronymic name. Five of the names are considered monophyletic and five are considered polyphyletic. Because each individual has two surnames, information about the name complementary to the selected surname was analyzed using isonymy methods (1) to see the effect of immigration on the genetic composition of the population and (2) to determine the isonymy, the relationship by isonymy within and between the persons with monophyletic and polyphyletic surnames. The percentages of the most common complementary surnames, the coefficients of relationship by isonymy of surnames for a selected surname, and the coefficients of relationship between the selected surnames are higher in the monophyletic than in the polyphyletic surnames, indicating that the persons with monophyletic names still conserve some customs of the founders that possibly increase their degree of endogamy. Perhaps these indicators are inversely related to migration, indicating that the monophyletic surnames have been more stable in Monterrey since it was colonized.

Birth order, sibship size, and risk of epilepsy.

We examined the relation between epilepsy and birth order, using data on 1,950 probands with epilepsy and 4,636 of their full siblings without epilepsy from the Epilepsy Family Study of Columbia University. The proportion of first-born individuals appeared to be higher among probands with epilepsy than among their unaffected siblings, but this relation disappeared after we controlled for the confounding effect of sibship size. With sibship size controlled, the proportion of first-born individuals was similar to that in unaffected siblings for probands with idiopathic/cryptogenic epilepsy, generalized and partial onset seizures, and all ages at onset of epilepsy. Probands with remote symptomatic epilepsy had higher birth orders than their unaffected siblings, even after we controlled for sibship size.

Pruebas de tamizaje para la detección de errores congénitos del metabolismo / Screenin tests for inborn errors of metabolism

Existe un gran número de errores congénitos del metabolismo asociados a anormalidades clínicas entre las que destaca el retardo mental, y que pueden prevenirse si se detecta y aplica la terapia adecuada y portuna. En este trabajo se presentan los resultados obtenidos aplicando pruebas de tamizaje metabólico (PTM) en 1485 muestras de orina de pacientes de la consulta pediátrica del Hospital General de Zona No. 21 y Hospital Regional de Especialidades No. 25, así como de clínicas del IMSS en el área metropolitana de Monterrey, Nuevo León, a las cuales se les realizaron pruebas químicas cualitativas para la determinación de aminoácidos, mucopolisacáridos, ácidos orgánicos y azúcares, así como cromatográficas. En una segunda ocasión solamente 44.83 y 57.02 por ciento respectivamente, dieron nuevamente una prueba positiva, por lo que se sugiere que médico responsable debe de enviar una segunda muestra con información sobre factores que puedan influir en los resultados

Genetic structure of the populations migrating from San Luis Potosi and Zacatecas to Nuevo León in Mexico.

The Mexicans residing in the Monterrey metropolitan area in Nuevo León, Mexico, were grouped by generation and birthplace [Monterrey Metropolitan Area (MMA), San Luis Potosi (SLP), and Zacatecas (ZAC)] of the four grandparents to determine the extent of genetic variation within this population and the genetic differences, if any, between the natives living in the MMA and the immigrant populations from SLP and ZAC. Nine genetic marker systems were analyzed. The genetic distance analysis indicates that SLP and ZAC are similar to the MMA, irrespective of birthplace and generation. Gene diversity analysis (GST) suggests that more than 96% of the total gene diversity (HT) can be attributed to individual variation within the population. The genetic admixture analysis suggests that the Mexicans of the MMA, SLP, and ZAC, stratified by birthplace and generation, have received a predominantly Spanish contribution (78.5%), followed by a Mexican Indian contribution (21.5%). Similarly, admixture analysis, conducted on the population of Nuevo León and stratified by generation, indicates a substantial contribution from the MMA (64.6%), followed by ZAC (22.1%) and SLP (13.3%). Finally, we demonstrate that there is no nonrandom association of alleles among the genetic marker systems (i.e., no evidence of gametic disequilibrium) despite the Mestizo origin of this population.

[Effect of sodium diphenylhydantoin on sister chromatid exchange frequency in mice]. / Efecto del difenilhidantoinato de sodio (DFH) sobre la frecuencia de intercambio de cromátides hermanas (ICH) en ratones.

In order to analyze the effect of the anticonvulsant diphenyl hydantoin (DPH) over the frequency of sister chromatid exchanges (SCE) in vivo, Balb-C mouse 8-12 weeks old, males and females, were injected intraperitoneally with a single dose and three different concentrations: 1, 10 and 20 mg/Kg, as negative and positive control, we used physiological serum and mitomycin-C respectively that were injected in the same way. Twenty five metaphases were analyzed per individual in the slide with the differential staining of sister chromatid, we found a light, but significantly increase, in the frequency of SCE in the concentrations of 10 and 20 mg/Kg when they were compared with the ones obtained for the negative control. In the males was observed a positive correlation in the levels of ICH when the doses of DPH were increased.

[Frequency of color blindness and glucose-6-phosphate dehydrogenase enzyme deficiency in non-industrialized populations in the state of Nuevo León, México]. / Frecuencia de la ceguera para los colores y de la deficiencia a la enzima glucosa-6-fosfato-deshidrogenasa en poblaciones no industrializadas del Estado de Nuevo León, México.

In order to know if there would be genetic structural differences among non industrial and industrial populations, two genetic markers were studied: color-blindness (CPC) and glucose-6-phosphate dehydrogenase deficiency (G6PD), in students, males and females that were resident in five non industrial populations in the State of Nuevo Leon. The results were compared with the information for industrial zone from the Monterrey Metropolitan area (AMM). It was found that the frequencies of CPC and G6PD in non industrial populations (2.57 and 0.00 per cent), were lower than the ones in the industrial AMM (4.0 and 0.66 per cent), probably as a result that in the first populations, with minor urbanization, the main factors that influence are: natural selection, interacial mixed or genetic drift and the second population is the immigration, since 1940 to present time, of Mexican populations with greater influence from the Indians and Africans.

[Relative frequency of glucose-6-phosphate dehydrogenase deficiency in jaundiced newborn infants in the metropolitan area of Monterrey, Nuevo León]. / Frecuencia relativa de la deficiencia de glucosa-6-fosfato deshidrogenasa (G6PD) en neonatos ictéricos del área metropolitana de Monterrey, Nuevo León.

In order to estimate the frequency of G6PD deficiency in the icteric population of the Monterrey metropolitan área (MMA), in the state of Nuevo León, there were studied 829 newborn males were studied. It was found that 13 subjects were deficient of this enzyme, that is equivalent to a frequency of 1.57% and when this frequency was compared with the one that was found an a previous study in a random sample of newborn males (0.66%) no statistical difference was observed, but it was estimated that the icteric newborn males have a relative risk of 2.34 times higher than the population in general to be a G6PD deficient, and this fact suggests the necessity to establish this screening test as a routine for all icteric newborn males, in order to have an opportune detection and an appropriate counselling.

[Activity of ribosomal genes and the association with acrocentric chromosomes in trisomy 21 and habitual abortion]. / Actividad de genes ribosomales y asociación de cromosomas acrocéntricos en la trisomía 21 y el aborto habitual.

The frequency of silver stain of the nucleolus organizer regions (NOR's) an indicator of the transcriptional activity of the DNAr, and the frequency of the association between acrocentric chromosomes (A.A.C.), possible indicator of the non-disjunction risk, were studied in the chromosomes in metaphase of eight married couples with regular 21 trisomy children, five couples that have had consecutive miscarriages and fifteen control normal persons, eight men and seven women. In this three groups the mean age was 30 years and they were compared according to sex. Another seven couples, with a mean age of 52 years also parents of 21 trisomic were compared against the group of young parents of 21 trisomics in order to analyze the age effect. Moreover there were studied the trisomic children of eight of the above couples in order to find out the effect of the supernumerary 21 chromosome. In all the groups the correlation coefficients between the frequency of NOR's-Ag+ and the A.A.C. were determined. It was found that the young group of parents of trisomic and the couples with consecutive miscarriages, both men and women, had a significant increased frequencies of NOR's-Ag+ and A.A.C. in comparison to controls. In the parents of trisomic, either men or women it was found a significant diminished level in the frequency of NOR's-Ag+ when the age increased, meanwhile raise in the frequency of A.A.C. with the increase of age was observed only in the women. A positive correlation between the frequencies of NORs-Ag+ and A.A.C. was found in the women of the control group and in the young mothers of trisomic.(ABSTRACT TRUNCATED AT 250 WORDS)

[Deficiency of glucose-6-phosphate dehydrogenase in a family]. / Deficiencia de glucosa-6-fosfato deshidrogenasa (G6PD) en una familia.

The erytrocyte glucose-6-phosphate deshydrogenase (G6PD) identification and activity were determinated in all member of a family, which was selected because one of the sons showed the clinical signs of hemolitic anemia due to G6PD deficiency and this was confirmed by qualitative fluorescent test, enzyme activity quantification and electrophoretic runs. It was found that two clinically healthy brothers are G6PD deficients and that the mother and one sister are carriers of this enzimatyc defect of the A--variant. As an antecedent it was found that the propositus mother received chloramphenicol treatment for ten days during the first three months of pregnancy. The advantages of the opportune enzymatic studies, with the objective to avoid hemolitic crisis in those G6PD deficient persons, are commented.

Variation in the gene frequencies of three generations of humans from Monterrey, Nuevo León, Mexico.

Allele frequencies for the ABO, Rh, MNSs, Duffy, Kidd, Lutheran, P and Lewis blood group systems in 207 persons whose 4 grandparents were born in the Monterrey Metropolitan area (MMA), grouped into 3 generations, were ascertained along with other related population from the MMA, Mestizos from Saltillo, Coahuila and Tlaxcala, and from the populations thought to have contributed to their genetic constitution (native Mexican Indians and Spanish). Genetic admixture and distance estimates were calculated. Gene frequencies of the three generations from MMA are intermediate to those of the ancestral populations, indicating that they are Mestizo but with a genetic structure different from Mestizos of Saltillo and Tlaxcala. Both genetic admixture and distance estimates indicate that the oldest generation exhibits the greatest Spanish influence which decreases in the youngest generation and in the other MMA populations as a result of the immigration from the central states of Mexico.

[Preferences on family composition among youngsters from Monterrey, Mexico]. / Preferencias sobre la composición familiar entre jóvenes de Monterrey, México.

In order to evaluate the effect of social and biological factors on family size (FS) and secondary sex ratio (SSR) in the families that they would desire to procreate as well as in the ones to which they belong, 1,518 unmarried persons of both sexes, students and workers, who reside in the metropolitan area of Monterrey, Mexico were interviewed. It was found that the average FS desired by the unmarried males and females, independently of their socioeconomic level and years of schooling, were 3.19 and 3.04, which are lower than half the FS of 6.81 observed in the families to which they belong. Both males and females in all the socioeconomic levels and years of schooling, would desire to procreate a larger number of male children: SSR of 0.576 and 0.524, which are higher than the 0.498 observed in the families to which they belong. Also they manifested a strong preference for the birth order of the sex of their children, being of males for the first (SSR of 0.924 and 0.838) and of females for the second (SSR of 0.301 and 0.269). The fact that all children would be of the same sex did not change the desired FS in about 80% of the persons, but in the remainder 20% the desired FS would be increased to an average of five children. In order to reduce the growth rate it would be convenient to offer special counseling on family planning to these persons. In conclusion, the obtained information indicates that aside from the socioeconomic, cultural and biological factors, probably the family planning programs have had a positive influence on the persons that in the near future will start their reproductive stage, and it is possible to anticipate a reduction on the growth rate for the next generation.

The effect of diphenylhydantoin on the frequency of micronuclei in bone-marrow polychromatic erythrocytes of mice.

Using the micronucleus test to evaluate the mutagenic effect of 5,5-diphenylhydantoin (DPH) on bone marrow polychromatic erythrocytes, male Balb-C mice were treated with the drug in single and multiple injection tests. A significant increase in the frequency of micronucleated polychromatic erythrocytes (MPE), P less than 0.05, was found when the mice received a single injection of DPH at doses of 0.5 and 1.0 mg/kg, and this frequency did not increase at higher doses. When mice were treated 3 times, at 24-h intervals, with 1.0 mg/kg of DPH, a significant increase in MPE was also observed (P less than 0.05) but this was lower than when they received a single injection of the same dose. A cytotoxic effect of NaOH, 0.1 N, which was used as solvent, was also observed either when alone or when DPH (1.0 mg/kg) was injected 3 times. This effect was comparable to the one produced by mitomycin C (MMC) at a dose of 0.5 mg/kg.